Adaptation values MSS65

Functional description, see BMW Service Technology:

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SBT number:

• 11 04 04 097
  

List of the adaptation values with target values

Description of the adaptations

1. Idling
   Idle speed is set by the DME via the idle actuator to the relevant nominal value. Control of the idle speed is based on torque. If there are deviations from the nominal idle speed, the speed is adapted by increasing or reducing the engine torque. This increase or decrease is recorded in the idle-speed adaptation. Positive values mean that the idle actuators are opened further.
   
2. Air leak
   The air leak adaptation compares the filling measured by the mass air flow sensor with the filling calculated by the DME. The DME uses the torque requirement to calculate the relative filling and thus the necessary opening cross section. The adaptation is active at idle speed with the engine at operating temperature. The main cause of deviations is the changed gap in the closed throttle valves.
   In the case of greater gaps, the adaptation deviates negatively. Vehicles with longer service lives tend towards positive values; often it is then sufficient to clean the throttle valve assembly.
   On troubleshooting, the difference between air leak and excess air is to be observed:
   
   • Excess air is caused by leak in the intake area towards the outside.
     
   • Air leak is caused by the gaps of the throttle valves.
     
   The air leak adaptation does not react to excess air! In the case of excess air, the lambda adaptation and oxygen-sensor control react. The offset value of the lambda adaptation then deviates positively.
   
3. Throttle valves / idle actuator
   Sequence of throttle-valve adaptation:
   
   • The throttle valves are pressed by the DME into the 'closed' limit position.
     
   • The activation is stopped and the throttle-valve sensor value that is then measured is stored as the adaptation value.
     
   Sequence of idle-actuator adaptation:
   
   • The idle actuators are pressed by the DME into the 'open' limit position.
     
   • The idle-actuator sensor value that is then measured is stored as the adaptation value.
     
4. VANOS
   The DME learns the end stop of the VANOS from the limit position adaptation.
   The valve quality enables conclusions to be drawn regarding the operability of the VANOS solenoid valves. Contamination of the solenoid valves has a major influence on the operability of the solenoid valves. The greater the adaptation value, the better the valve quality.
   
5. Accelerator pedal module
   The voltage values of the two Hall sensors in the accelerator pedal module are measured in idle position and stored as adaptation values.
   
6. Oxygen-sensor control
   The lambda adaptation shifts the control status of the oxygen-sensor control.
   
   • Factor: greater than 1 means enrich (active in the range of greater injection quantities)
     
   • Offset: positive values mean enrich (active in the range of smaller injection quantities)
     
7. Knock Control
   Knocking cylinders are statistically evaluated by the Digital Engine Electronics and the result is used to calculate a retraction angle. This retraction angle is stored as an adaptation value.
   With the engine running, the current ignition timing is corrected with the adaptation value. Depending on the operating range, the adaptation value is weighted.
   
   • Negative value: correction in direction retarded
     
   Possible influences on the knock adaptation:
   
   • Fuel quality
     
   • Fault at an intake air temperature sensor
     
   • Oil coking, oil consumption
     
   • Fault at the spark plugs
     
8. Filling control
   In various operating modes, the filling control compares the filling measured by the mass air flow sensor with the filling calculated by the DME. The determined deviation is stored in the form of a factor as adaptation value.
   The adaptation can be used primarily to evaluate the characteristic curves of the mass air flow sensor. The measuring range of the mass air flow sensor here is divided into 8 ranges.
   Note on using the adaptation for troubleshooting:
   
   • Even if only one of the 8 range values deviates, the informative value is restricted.
     
   • If only the adaptation of filling control indicates non-permitted deviations in a number of ranges, this indicates a defective mass air flow sensor. In the case of excess air, additional oxygen-sensor control faults would also have to be stored and the idle-speed adaptation would have to deviate.
     
   • Oil coking, oil consumption
     
   • Fault at the spark plugs
     
9. Catalytic converters
   This catalytic converter adaptation checks the oxygen accumulation capability of the catalytic converters. If there are deviations from the target values, the system test for catalytic converters must be run.
   
10. Trimming control
    The trimming control checks the ageing of the oxygen sensors and catalytic converters. The adaptation value is used to influence the oxygen-sensor control.
    
11. Fuel pressure control
    With the engine running and low fuel requirement, the regulation of the desired fuel delivery pressure requires a certain cycle ratio for activation of fuel pump 1. This cycle ratio is compared with the cycle ratio that the DME calculates for the pilot control function.
    Deviations in the two cycle ratios are stored as an offset and as a factor. This corrects the cycle ratio of the fuel pressure control. The offset value corrects cycle ratios at low loads; the factor corrects cycle ratios at higher loads.
    Possible influences on the fuel pressure control adaptation:
    
    • Fuel filter clogged
      
    • Soiled or worn collectors of the fuel pump 1, above all with long running periods.
      
    • Internal leak in the fuel pump 1 due to wear, above all with long running periods.
      
    These influences increase the factor.